Silicon carbide crystal growth method and equipment capable of adjusting component balance

Abstract

The invention provides a silicon carbide crystal growth method and equipment capable of adjusting component balance, the equipment comprises a cavity, a graphite crucible, a heater and a growth tank, the graphite crucible and the heater are fixed in the cavity, a porous partition plate is horizontally arranged in the graphite crucible, the porous partition plate divides the graphite crucible into a crystal growth cavity and an auxiliary cavity, a silicon carbide raw material is contained in the crystal growth cavity, an auxiliary crucible is movably connected in the auxiliary cavity through a lifting assembly, and a silicon-rich raw material is contained in the auxiliary crucible; and the heater is used for uniformly heating the crystal growth cavity. The equipment comprises the graphite crucible and the auxiliary crucible adjusted by the lifting assembly, and along with continuous growth of crystals, the height of the auxiliary crucible is adjusted by the lifting assembly, so that silicon elements are supplemented into a silicon carbide raw material in the crystal growth process, and the balance of carbon components and silicon components in the silicon carbide raw material is adjusted; and the defects such as spiral dislocation, dislocation and microtubulation of silicon carbide crystals are avoided, and meanwhile the utilization rate of silicon carbide raw materials is increased.

Description

technical field [0001] The invention relates to a silicon carbide crystal growth method and equipment for adjusting component balance, and belongs to the technical field of silicon carbide crystal growth. Background technique [0002] The industrial growth of silicon carbide crystals mainly adopts the physical vapor transport (PVT) method, that is, the gas generated by the sublimation and decomposition of silicon carbide raw materials is transported to the seed crystal for recrystallization by heating above 2100 ° C, and a larger area of ​​silicon carbide (SiC ) single crystal. [0003] But at high temperature, silicon (Si) element and silicon-rich atomic groups are easier to escape from the raw material and transported into the growth chamber space, so the silicon element in the raw material is faster than the carbon (C) element during the crystal growth process. The carbonization of the raw material (that is, the C content in the raw material is higher than the Si content...

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Problems solved by technology

[0003] But at high temperature, silicon (Si) element and silicon-rich atomic groups are easier to escape from the raw material and transported into the growth chamber space, so the silicon element in the raw material is faster than the carbon (C) element during the crystal growth process. The carbonization of the raw material (that is, the C content in the raw material is higher than the Si content), after carbonization, the raw material will produce carbon-rich atomic groups, which will deposit on the crystal to form inclusion defects, and the inclusion defects will further grow into screw dislocations, layer Larger-scale defects such as faults and micropipes seriously affect the crystal quality of silicon carbide, which in turn affects the yield and product quality of downstream processes such as epitaxial process and device process; at the same time, crystal growth must be stopped when the raw material carbonization is serious, resulting in A large amount of waste, the ratio of the weight of crystals obtained in the industry to the weight of raw materials input is less than one-third, and the waste of raw materials is serious

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